Calling station identification circuit



March 16, 1954 D. s. BARL'ow CALLING STATION IDENTIFICATION CIRCUIT Filed Jan. 28, 1950 1'7 Sheets-Sheet 1 ATTORNEY Marchl 16, 1,954

D. s. BARLow CALLING STATION IDENTIFICATION CIRCUIT Filed Jan. 28, l195o 17 Sheets-Sheet 2 Nvmm Qmmm

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/NVENTOR D. BARLOW Arron/wir D. s. BARLow 2,672,515

CALLING STATION IDENTFIcATIoN clRcuI'r 17 Sheets-Sheet 3 March 16, 1954 Filed Jan. 28, 195o A TTORNE' Y March 16, 1954 Filed Jan. 28, 1950 D. S. BARLOW CALLING STATION IDENTIFICATION CIRCUITi 17 Sheets-Sheet 4 SECONDARY NErwo/a/r SDH g es" /Nl/ENTOR D. S. BARLOW BV March 16, 1954 D. s. BARLow CALLING sTATIoN IDENTIFICATION CIRCUIT 17 Sheets-Sheet 5 Filed Jan. 28, 1950 Arrob'A/Ey March 16, 1954 D s. BARLOW I 2,672,515

CALLING STATION IDENTIFICATION CIRCUIT Filed Jan. 28, 1950 1'7 Sheets-Sheet 6 l# )WEA/rop *rk s By D BARLOW m bQ: lk

A TTORNE V ARLW /Nl/ENTOR 1'7 Sheets-Sheet 7 D. S. BARLOW CALLING STATION IDENTIFICATION CIRCUIT k .um

March 16, 1954 Filed Jan. 28, 1950 ATTORNEY March 16, 1954 D. s. BARLow CALLING STATION IDENTIFICATION CIRCUIT 1'7 Sheets-Sheet 8 Filed Jan. 28, 1950 /NVENTOR D. S. BARLOW a y A Troma/Ev March 16, 1954 D. s. BARLow CALLING STATION IDENTIFICATION CIRCUIT 17 Sheets-Sheet 9 Filed Jan. 28, 1950 ATTORNEY March 16, 1954 v DI S BARLOW 2,672,515

CALLING STATION IDENTIFICATION CIRCUIT Filed Jan. 28, 1950 v17 Sheecs-SheefI 10 /NVEA/ro@ D. 5. BARLOW I ATTORNEY March 16, 1954 D 5 BARLQW 2,672,515

CALLING STATION IDENTIFICATION CIRCUIT Filed Jan. 28, 1950 17 Sheets-Sheet ll D \l N v /l k 'Q '2 k D b n E, b b n s S s C b l' b D 8 i5 m I k u Q5 /NVENTOR Q 8 l1 y as.AR/.0W

I l BV lmr a! CUN-gvd? A 7' TORNEV D. s. BARLow 2,672,515

CALLING STATION IDENTIFICATION CIRCUIT 17 Sheets-Sheet 12 March 16, 1954 Filed Jan. 28, 195o W &\ QH R0 mL R NA ma A l fs. M D. Vr B Qm\ S SG n n HUD kUWU .WQOQ

A TTORNEV March 16, 1954 D. s. BARLow 2,672,515

CALLING STATION IDENTIFICATION CIRCUIT Filed Jan. 28, 19.50 17 Sheets-Sheet 13 /N VERTE RS /NVENTOR Q ,St By* 0.5 BARLOW Qi lb m gg D A TTORNEV D. S. BARLOW CALLING STATION IDENTIFICATION CIRCUIT March 16, 1954 v1'7 sheets-sheet 14 Filed Jan. 28, 1950 mvg/v70@ D. S. BARLOW ArToRN/fw March 16, 1954 D. s. BARLow 2,672,515

` CALLING STATION IDENTIFICATION CIRCUIT Filed Jan. 2a, 195o v 17 sheets-sheet 15 RECORDER MAGNETS (LAW) /NvENro/P D. 5. BARLOW ATTORNEY F/G l5 nscnosn REG/s rens March 16, 1954 D 5 BARLQW 2,672,515

CALLING STATION IDENTIFICATION CIRCUIT Filed Jan. 28, 1950 1'7 Sheets-Sheet 16 x I D I l a 2% lu *I` Il '95h luk \Q tb n: Q l kx. Rb Sl@ /NVENTOOW B y D 5 BAR l 'W v ArroRA/Ev March 16, 1954 D. s. BARLOW CALLING STATION IDENTIFICATION CIRCUIT 17 Sheets-Sheet 17 Filed Jan. 28, 1950 /NI/EA/TOR D. 5. BARLOW Patented Mar. 16, 1954 CALLING STATION IDENTIFICATION CIRCUIT Dick S. Barlow, Port Washington, N. Y., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application January 28, 1950, Serial No. 141,141

38 Claims.

This invention relates to identification devices and particularly to devices for determining the directory number of telephone stations and other specific information individual to the stations, which may be useful in the billing of connections established therefrom, or for other purposes.

The identification of the directory number of a telephone station presents difliculties in those telephone systems where the directory number of a station differs from that of the equipment terminal to which the line of the station is connected in the central office. Particularly is this true in the case of party lines, for example, where a plurality of stations are connected to one line which has but one equipmentterminal number, while each of the stations thereon has an individual directory number. The problem of directory number identication is further complicated by P. B. X line groups, each line in ing its own directory number but which, for purposes of billing, it may be desirable to identify the directory number of some other line or some arbitrary directory number to which the call is to be charged, rather than that of the line which established the call.

Further difficulties also arise in those identiii cation arrangements which are adapted to identify the line or station with apparatus which is responsive to an identifying signal applied to a conductor of the line or the extension thereof. For instance, if the signal comprises a high frequency potential, crosstalk may be induced in other conductors included in the same cable as the conductor to which the signal is applied,

which will result in the signal being induced in said other conductors. Again, if the conductor the signal energy, reduce its intensity and thereby impair the operation of the detecting apparatus, the latter result also occurring if, for any reason, the continuity of the signal is interrupted or its amplitude is reduced by transient disturbances such as inductive interference, short circuits, momentary opening of contacts and the like.

It is the main object of the present invention to achieve a station identifier which is free from the above defects, is rapid in operation, is self checking to insure accuracy of identification, contains a minimum number of moving parts and is relatively of sirnpleconstruction to yield low cost of equipment and low cost of maintenance.

A particular feature ofthe invention is the provision as part of the identifier of a number of primary networks of passive electrical elements, one such element being'provided in one of the networks for each directory number to be identified through such network, the elements in each network being so interconnected by conductive paths that low-loss signal transmission is afforded along paths indicativeof the directory number to be identified and high-'loss signal transmission is afforded along all other paths.

Another feature of the invention is the provision of two similar but secondary networks of passive electrical elerrients foreach primary network and of substantially similar electrical properties as a primary network, by'means of which each of the digits of the directory number indicated by the presence of the identifying signal along certain conducting paths offa primary network is compressedinto a'suitable code that expresses the digit. It is obvious, of course, that a suitable signal-detecting unit could be provided at each conductive path of a primary net Work, and by the response of appropriate detecting units to the signal on certain of the paths, provide an identification of the number'. Such an arrangement, however, while entirely feasible and included as part of the present invention, involves the use of an excessive'amont of detecting equipment. The two secondary networks of passive elements are, therefore', provided with each primary network in order that 'the ten values of each digit' of the number may be ek-` pressed by a uniform code which involves at each pair of secondary networks 'a 'less number' of conductive paths than in the associated' primary network. This arrangement makesit possible tion impedance substantiallyreduces crosstalk over sleeve conductors, noise, power consumption and other undesirable disturbing factors. l

Still another featurepf the invention is the provision yof a: discriminating device as a, part off the iuenti'ei by, means .o fnwhicn the integrity,

signal atthepassive 'elements of the identifyingv of a particular pair of secondary networks is secondary networks and, further, a class" netchecked for the proper frequency, amplitude and work;

duration before it is accepted for transmission Figs. 5, 6, 7 and 8 show the four input gate to the registers which are to be set in accordance circuits, each one associated with one pair of therewith for registering the identiiied directory secondary networks; number. Fig. 9 shows the Digit Scanning circuit;

Still another features of tlije invention; is:. a Figui() shows the Sleeve Impedance Check circheck circuit associated with the'signal source Guit" which, at the time lan identification is to be Fig. 1l shows the live Number circuits of which made, measures the impedance 0f the sleeve con* l'Number Circuit No. 1 is shown in detail and the ductor of the connection and whichnif'tliewaiuef; 0ther,four..areeindicated schematically;

thereof is more or less than a predeterminedoV Fig. 12'shows the Code Check circuit; value, prevents the identifier fromV proceeding Fig., 13 ShOWS the Output circuit, llludillg the with further operations. digi-t'registeras;

In using the identifier to `iderniiifygth1e;;d.irectory; 15 Fig-14showsthefrecorder registers of the rst number of a calling station, for example, its utilityl recorder,togetherwith the recording magnets of lies in causing a record to begrnadep. thigiideng. Saidurecordel,

tied number, which record is subsequentlyused Fig, 15 shows the recorder registers of the last for charging the can to the station that made-it; recorder;` together wththc recorder magnets of In a telephone exchange adapted for the ausaid recorder;

tomatic.recordingiotitems;oiirecord information; Figi'16S-shoWs-1therregisters in the: callir'iiy Office mig memories-efficient practicesto:proiiidei one rea fon a.recor,derelocatedrinfasremoteioiice; and a.

cording f devicesforfneacli:` grou-p tot trunks over circuita for transmitting?. Codedi frequencyY irn- Which .connections -arefestabiishd and to associ-v pulses of a-numbenzregisteredinrthe ydigit register ate said. recordingdevicetemporarily:withatrunk r tofthefremotemia in.l fthe.I groupewheneven somet-iternf` offiniorni-a-v Figi. 17A; is 1.ag,.skeletonizedscircuit zdiagram zine tion-is .tobe'recorded in-respect-to atconnection dicatingz.certaimelectricalu characteristicssoi a established; or .zbeingf-sestablisl'iedgf, over :thel trunk; primary IIBWOITKI 1 According1y,.fit is another .feature off-thednvention Figc 17B ispanskeletonized arrangement=z ora to associates-.the=identiiiereeleotrorcallyt'with 30 portionzofiaiprimarytnetworlcxto.fbetter disclose thefseveral recording4 devioesnsthe exchange, certain Aother@ characteristics ci, said; network, to` .obtain the fdireci'nryifnumbers'identificationt :of While e a-.callingstationz extended tosaitrunki.- andl to Fig. lishowssthe mannenintwhichr'igsl to i6,

activate the one-,recordingsdeviceowhoh vhas face inclusive, shouldzbe larrimagedniv'itlfr respect to each cess tothe trunlergroup thatfincludesfsaicttrunk; other fin 4ordertoz disclose f-ithefrinvention :comthereby toitransmit th'eridentieddirectory :fmni-g pietelyrv per; oniyto the. recording-sdevice oassociatedewith I will mst-describe ,thief-arrangement and `funcsaid Itrunk. By fagnoszelu elec-:tronic`v arrangement tions of;- va-rioussparts; of- ;thef;di'sc1osure,. and will between-fthefidentienandzztlresseveral :recording then describe in detail-its operation.4 with respect devices, electromagnetic.; switching; apparatus 40 to'theaidentificationnan;recording1dof -arepreordinarily fused for-;establishingitemporary :cons4 sentative :directonymumberaof aicalling station1 nections het-weenntheidenti-ecranfidieachsoiftne Figzl showsa'itelephone-linein connected to several recordingdeiiicessasereuuired iisitherethe terminals,nrsaaswitchfLSl dma/ central office. by avoided -thus aconseiwing espace and -=.reducing The flinesis' protidcdswitrffour :telephrle' Stations thefcostroi'the apparatus-s 45 A, B, C and D each having anaindii/,idual idirecu It `is rscmetimesfdesirablc :intraitelephone .system tory vnunrber.;` Ait-gjceing;` assumed lfor purposes Vor' to record informationpertainingato -afconnection illustrationfthat; statinnn has :the :directory num,- at an;` exchangejremoteafrometne; exchangefzat. berf3847: WhenV azstatiorrfon the -linc yL, for -exwhich-the,A call' :is aoriginated. Accordinglyszitiis ample statiorxAsorignatesa Calltihe 1in@ iS @Xs another featnrefoftherprescntiinaentionitodprcc tended :in: thea-usuaifmanner over;switchingfsed vide for the transmissiom off; signals, 5 charace lectors fLSi lI iStfLSfX ',rofr-any--suitableconstructeristc of fangidentiedr directcryrnnmberfto :a tion,l to. :the trunk: fromwhich the` connecrecording; device at a-remoteilccation; andA 1to1 eff-A tion lispthen iurtnemextended iunder the control iect'this Ytransinissiornm*means;ioffiaypluralitnoi? offnziegister,senderginaccordance with the dialed frequencies -selectivelyi combined-:imc accordance callpedgocetcode registered therein. Since the vsf-hracpredetermineA ,codegtozarepresent eachaof, manner in which thcfline is extended to -and bethe digitsnof kithe idcntiedsnumber; yond thetrnnkxformsfno pactnofgthepresent in-r These and *other featuresotitheiinwentionewillventionygthe means bytwhichsuchf extensions are be more; clearlyiundepstogdefromgmeifollowing eiiectedsare :not showrnand '.Will'not be described. description.,appendedlairs end attached'iifaws 6C) Fig; 1 furthen show-ssa Jstationz identification ings-in which:` circuit.#S161which;;.wheniarelaytCI is f operated Figs bshoWs-fatelephone line L\i.'itl'i--fourtele-` inziany:sutablesmanner is .connected to the tip phone stations= thereon; afsw-itching train-by andlngfC0ndmt9fS'T1andRimfthetrum The which., melma 54mm-tied ,.t'oa-tmk? apvate circuit Sigmar-.be ,fofttheftype 3 disclose-d. in Patent branchemrfmge4me gru diwigcohec 65 ,No.;2;306;1'l3,gissuedftosM-niLogan-on'pecemher tions between;- the '.irla'rious lines and-,associated 2z 19421 21nd 'lt-.5"fpwposls; to derml'r 1W high equipment and"directprif* imioenterniinalsi I the uqlli? 'Dthas lgmat'ed Fig. 2 showsin detailorle ofthe Primary net-. e ca en'- .e e 'ermma lo as Peg f f i made-for exampleqm-the .finanner set Afoitn in Works 'of passi@ ellmr-ial Emmer-1335i- 70 the aboveidentiiiedpatent, the-identity (but not 1 11-1t1.191 50i th-Q W0 Slldaff. the directoryi rnnnlzterf.y oi- @i 5 *th th registered-ib "n 11.111 Eig., l relaysgaingc# ta., @gmane d il i partysregiste ,fthe-calling' station ris f;.one;cf; the;fou1 4 ,thesl'tien constituting pa Wilt? s, .ciment-temporarily-rase heetuunk yforniti-re -ftime z-,taicento identify the directory numberof a callingstation as hereinafter set forth, or is otherwise a permanent part thereof. Thus, for example,. if the call is originated by station A, the' ycircuit SIC will determine the fact and cause the operation of relay A of the party register, which relay,

vwhen operated, locks to off-normal groundover its locking winding to perform certain functions later to be described. In the same manner, if the call is originated by station B or C or D, the circuit SIC will make the appropriatestation identification and cause the operation of relays B or C or D, respectively,V in the trunk party register.

The sleeve terminal S of the line L is connected by a conductor to a terminal in the Equipment Number Terminals, indicated in Fig-gl by the vertical column of terminals under'` the legend Eqpt. No. Term. This terminal indicates the equipment location of the line on the line switch LSI. If, for example, the telephone exchange in which the invention is to be practiced has a capacity for 10,000 lines, there would be up to 10,000 such cross-connecting terminals in the Equipment Number Terminal group, each terminal in the group designating a particular location on the terminal banks orl contacts of the line switches to which a line is terminated. Conductors are then extended from the sleeve terminals S of the several lines in the oice to the equipment number terminals in accordance with the equipment terminal location or each of said lines. In the present embodiment of the invention, herein disclosed by way of illustration, it is assumed that the oice containing line L has a capacity of 10,000 lines. Accordingly, there would be up to 10,000 terminals in the Equipment Number' Terminal Group to which conductors from the sleeve terminals S ofthe line switches extend in accordance with the equipment location of the several lines connected to said line switches. It will be observed that, as illustrative of the general arrangement, the sleeve terminal S of the line L is extendedA by a conductor to the cross-connecting terminal 4000, indicating thereby that the line L terminates on a group of terminals (of which the sleeve terminal lS is one) in a line switch, which. group of terminals is numerically designated as 4000.

In many automatic telephone exchanges, particularly those in which the lines terminateon non-numerical switches of the cross-bar type, for example, there is no correlation between the equipment number termination of a line and the directory number assigned to the station on the line or, if there be more than one station on the line, to the directory numbers of the several stations thereon, except that, in general and for a 10,000 line exchange, the total number' of directory numbers is not less than the total oi' the equipment location numbers. Should there be lines in the exchange that have a plurality of stations thereon, as in the case of line L, 'for example, some of the equipment terminals in the vertical column of terminals Eqpt. No. Term. would be vacant. It is necessary, however, that each directory number assigned to a station be correlated with the equipment location number of the line to which the station is connected, and

since this correlation is purely an arbitrary one,`

the latter is established by suitable cross-com nections between thev equipment number te`r-v minals and another group of 10,000 cross-oonnecting terminals which, in Fig. l,l is illustrated Gf by the vertical column of terminals under the legend Dir. No. Term. (10,000). Between the equipment number terminals on Eqpt. No. Term.v

and the directory number terminals on Dir. No. Term. conductors are interposed in accordance with location numbers of the several lines and the assigned directory numbers of the station, or stations, on said lines. Thus, for example, it has been assumed that line L has anequipment location number of 4000. Accordingly, terminal S of the line is extended by a. conductor to cross-connecting terminal 4000 in Eqpt. No. Term. Line L, however, is provided with the four stations A, B, C and D of which it has been assumed that station A has the directory number 3847. Accordingly, a conductor is further extended from equipment location terminal 4000 in Eqpt. No. Term. Vto directory number terminal 3841 Eqpt. No.'Term. .In the same manner, three other conductors, one for each of the other three stations B, C and D, extend from 4000 in Eqpt. No. Term. to three other directory number terminals in Dir. No. Term. in accordance with the directory numbers severally assigned to the three stationsB, C and D. When a line contains but one station, then there would be but one conductory extending between the equipment number terminal in Eqpt. No. Term.

and a directory number `terminal in Dir. No.

Term.

For the purpose of the present invention, a Termination Network comprising a capacitor CI and resistor RI is connected as shown to each of the occupied directory number terminals, while a branch of the Termination, including resistor R2, is extended to a class terminal in the vertical group of terminals beneath the legend Class in accordance with the class of service to which the station is entitled. At the common terminal of the capacitorCl and resistors Ri and R2 of each Termination, a conductor i, 2, 3 or 4 extends to the primary networks shown in Figs. 2 and 3, in accordance with the directory number indicated by the directory number terminal ,f to which the conductor is connected, as more particularly set forth below.

The wiring arrangement at the equipment number and directory number terminals for the lines of a P. B. X is somewhat similar to that of individual lines and stations thereon, though slightly modified to permit the identification of the one directory number to which a call is to be charged regardless of the line in the group that initiates the call. For this purpose, all the directory number terminals of ra P. B. X line group are extended to a Collector Network comprising a resistor R3 for each terminal, connected in Parallel to a grounded common resistor R4, whence a conductor 5 further extends into one of the primary networks shown n Figs. 2 and 3 in accordance with the P. B. X directory number to which calls made from any line in the group are to be charged. As further explained below, and shown in the drawing, conductor 5 is connected vto a passive element Rl,l00 in primary network PDN-A, thereby indicating that the directory number to which calls made from the lines in the P. B. X group are to be charged to directory number '0, which is the number identified whenever a line in said P. B. X group originates a call, regardless of its own number.

It is thus evident from the above description that the wiring arrangementfindicated in Fig. 1 provides one "identifyng conductor individual to each of the directory numbers of the severall 

